The present invention relates to a pipe assembly for a solar heating device and more particularly to a pipe assembly adapted to provide ease of cleaning of the individual pipe sections and to control the flow of fluid through them.
Solar heating devices include an assembly of pipes through which a fluid, such as water, flows. The solar collector typically includes solar absorber panels which collect solar energy and transfers it through the pipes to the flowing water. The pipe assembly includes fluid inlet and outlet conduits and is enclosed in an insulated case with clear glazing to allow incident solar energy to pass through and be collected by the absorber panels. The pipes and absorber panels consist of metals of high conductivity to thereby provide the heat exchanging function of transfering solar energy absorbed by the panels to the water flowing through the pipes. These devices are shown in representative U.S. Pat. Nos. 966,070 to Bailey, 2,274,492 to Modine and 3,972,213 to Gallagher.
The fluid that flows through the pipes in these devices is usually hard water which causes fouling by the accumulation of scale on the inside of pipes. This scale acts as an insulator and reduces the efficiency of heat transfer from the pipes to the fluid flowing through the pipes.
The pipe assemblies for solar heaters are typically formed of an assembly of pipe sections with each section formed of a longitudinal tubular pipe which may be connected either in parallel or in series with a pumping unit connected to the assembly. The parallel assembly includes an inlet manifold which is common to all of the pipes for transmitting fluid into the pipes, and a discharge manifold also common to all the pipes, for discharging the fluid from the pipes.
In the parallel assembly, the pump unit is coupled to one end of the inlet manifold and the flowing fluid may be discharged from either end of the discharge manifold. The flow of fluid may therefore not be optimum through each tubular pipe section in the parallel assembly. Thus, less than optimum heat transfer may result in pipe sections of low flow rates. Conversely, erosion, or the gradual wearing away of the pipe material, may occur on the inside of pipe sections exposed to excessive flow rates.